lkml.org 
[lkml]   [2008]   [Mar]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Subject[PATCH 23 of 31] x86: unify pgd ctor/dtor
    Date
    From
    All pagetables need fundamentally the same setup and destruction, so
    just use the same code for everything.

    Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
    Cc: Andi Kleen <ak@suse.de>
    ---
    arch/x86/mm/pgtable.c | 59 +++++++++---------------------------------
    include/asm-x86/pgtable.h | 16 +++++++++++
    include/asm-x86/pgtable_32.h | 15 ----------
    include/asm-x86/pgtable_64.h | 2 -
    4 files changed, 30 insertions(+), 62 deletions(-)

    diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
    --- a/arch/x86/mm/pgtable.c
    +++ b/arch/x86/mm/pgtable.c
    @@ -59,50 +59,6 @@
    list_del(&page->lru);
    }

    -#ifdef CONFIG_X86_64
    -pgd_t *pgd_alloc(struct mm_struct *mm)
    -{
    - unsigned boundary;
    - pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT);
    - unsigned long flags;
    - if (!pgd)
    - return NULL;
    - spin_lock_irqsave(&pgd_lock, flags);
    - pgd_list_add(pgd);
    - spin_unlock_irqrestore(&pgd_lock, flags);
    - /*
    - * Copy kernel pointers in from init.
    - * Could keep a freelist or slab cache of those because the kernel
    - * part never changes.
    - */
    - boundary = pgd_index(__PAGE_OFFSET);
    - memset(pgd, 0, boundary * sizeof(pgd_t));
    - memcpy(pgd + boundary,
    - init_level4_pgt + boundary,
    - (PTRS_PER_PGD - boundary) * sizeof(pgd_t));
    - return pgd;
    -}
    -
    -void pgd_free(struct mm_struct *mm, pgd_t *pgd)
    -{
    - unsigned long flags;
    - BUG_ON((unsigned long)pgd & (PAGE_SIZE-1));
    - spin_lock_irqsave(&pgd_lock, flags);
    - pgd_list_del(pgd);
    - spin_unlock_irqrestore(&pgd_lock, flags);
    - free_page((unsigned long)pgd);
    -}
    -#else
    -/*
    - * List of all pgd's needed for non-PAE so it can invalidate entries
    - * in both cached and uncached pgd's; not needed for PAE since the
    - * kernel pmd is shared. If PAE were not to share the pmd a similar
    - * tactic would be needed. This is essentially codepath-based locking
    - * against pageattr.c; it is the unique case in which a valid change
    - * of kernel pagetables can't be lazily synchronized by vmalloc faults.
    - * vmalloc faults work because attached pagetables are never freed.
    - * -- wli
    - */
    #define UNSHARED_PTRS_PER_PGD \
    (SHARED_KERNEL_PMD ? KERNEL_PGD_BOUNDARY : PTRS_PER_PGD)

    @@ -120,7 +76,8 @@
    ptes in non-PAE, or shared PMD in PAE), then just copy the
    references from swapper_pg_dir. */
    if (PAGETABLE_LEVELS == 2 ||
    - (PAGETABLE_LEVELS == 3 && SHARED_KERNEL_PMD)) {
    + (PAGETABLE_LEVELS == 3 && SHARED_KERNEL_PMD) ||
    + PAGETABLE_LEVELS == 4) {
    clone_pgd_range(pgd + KERNEL_PGD_BOUNDARY,
    swapper_pg_dir + KERNEL_PGD_BOUNDARY,
    KERNEL_PGD_PTRS);
    @@ -148,6 +105,17 @@
    pgd_list_del(pgd);
    spin_unlock_irqrestore(&pgd_lock, flags);
    }
    +
    +/*
    + * List of all pgd's needed for non-PAE so it can invalidate entries
    + * in both cached and uncached pgd's; not needed for PAE since the
    + * kernel pmd is shared. If PAE were not to share the pmd a similar
    + * tactic would be needed. This is essentially codepath-based locking
    + * against pageattr.c; it is the unique case in which a valid change
    + * of kernel pagetables can't be lazily synchronized by vmalloc faults.
    + * vmalloc faults work because attached pagetables are never freed.
    + * -- wli
    + */

    #ifdef CONFIG_X86_PAE
    /*
    @@ -246,7 +214,6 @@
    pgd_dtor(pgd);
    free_page((unsigned long)pgd);
    }
    -#endif

    int ptep_set_access_flags(struct vm_area_struct *vma,
    unsigned long address, pte_t *ptep,
    diff --git a/include/asm-x86/pgtable.h b/include/asm-x86/pgtable.h
    --- a/include/asm-x86/pgtable.h
    +++ b/include/asm-x86/pgtable.h
    @@ -344,6 +344,22 @@
    pte_update(mm, addr, ptep);
    }

    +/*
    + * clone_pgd_range(pgd_t *dst, pgd_t *src, int count);
    + *
    + * dst - pointer to pgd range anwhere on a pgd page
    + * src - ""
    + * count - the number of pgds to copy.
    + *
    + * dst and src can be on the same page, but the range must not overlap,
    + * and must not cross a page boundary.
    + */
    +static inline void clone_pgd_range(pgd_t *dst, pgd_t *src, int count)
    +{
    + memcpy(dst, src, count * sizeof(pgd_t));
    +}
    +
    +
    #include <asm-generic/pgtable.h>
    #endif /* __ASSEMBLY__ */

    diff --git a/include/asm-x86/pgtable_32.h b/include/asm-x86/pgtable_32.h
    --- a/include/asm-x86/pgtable_32.h
    +++ b/include/asm-x86/pgtable_32.h
    @@ -104,21 +104,6 @@
    #else
    # include <asm/pgtable-2level.h>
    #endif
    -
    -/*
    - * clone_pgd_range(pgd_t *dst, pgd_t *src, int count);
    - *
    - * dst - pointer to pgd range anwhere on a pgd page
    - * src - ""
    - * count - the number of pgds to copy.
    - *
    - * dst and src can be on the same page, but the range must not overlap,
    - * and must not cross a page boundary.
    - */
    -static inline void clone_pgd_range(pgd_t *dst, pgd_t *src, int count)
    -{
    - memcpy(dst, src, count * sizeof(pgd_t));
    -}

    /*
    * Macro to mark a page protection value as "uncacheable". On processors which do not support
    diff --git a/include/asm-x86/pgtable_64.h b/include/asm-x86/pgtable_64.h
    --- a/include/asm-x86/pgtable_64.h
    +++ b/include/asm-x86/pgtable_64.h
    @@ -24,7 +24,7 @@

    #endif /* !__ASSEMBLY__ */

    -#define SHARED_KERNEL_PMD 1
    +#define SHARED_KERNEL_PMD 0

    /*
    * PGDIR_SHIFT determines what a top-level page table entry can map



    \
     
     \ /
      Last update: 2008-03-18 06:29    [W:0.026 / U:0.052 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site